Time Zone History

Adelaide time zone history

Its standard time, UTC+9:30, is one of only 14 offsets among the 312 zones that are not a whole number of hours from UTC. On standard time, clocks in Adelaide run 16 minutes ahead of local mean solar time.

UTC+9:30

Standard time is UTC+9:30 (ACDT/ACST); clocks go forward to UTC+10:30 on the first Sunday in October and back on the first Sunday in April.

Covers: South Australia · tz database name Australia/Adelaide

Convert a time from Adelaide

Summer time in 56 of 57 years since 1970

UTC+9, UTC+9:14:20: behind today’s standard timeUTC+9:30: today’s standard timeUTC+10:30: 1 hour ahead of today’s standard timeUTC+9, UTC+9:14:20: behind today’sstandard timeUTC+9:30: today’s standard timeUTC+10:30: 1 hour ahead of today’sstandard time

How to read this chart

Before 1970

18901910193019501970189019301970
JanFebMarAprMayJunJulAugSepOctNovDec1970198019902000201020202028JFMAMJJASOND1970198019902000201020202028

Standard time changes

DateChangeNew standard timeClock label
Before 1970
February 1, 1895Local mean time (UTC+9:14:20) replacedUTC+9ACST
May 1, 1899Standard time forward 30 minutesUTC+9:30ACST

Daylight saving periods

YearsClocks go forwardClocks go backShift and labels
Before 1970
1917January 1March 251 hour, ACST to ACDT
1942January 1, September 27March 291 hour, ACST to ACDT
1943October 3March 281 hour, ACST to ACDT
1944not that yearMarch 261 hour
Since 1970
1971October 31not that year1 hour, ACST to ACDT
1972October 29February 271 hour, ACST to ACDT
1973–1985last Sunday in October, 02:00first Sunday in March, 03:001 hour, ACST to ACDT
1986October 19March 161 hour, ACST to ACDT
1987–1990last Sunday in October, 02:00third Sunday in March, 03:001 hour, ACST to ACDT
1991October 27March 31 hour, ACST to ACDT
1992October 25March 221 hour, ACST to ACDT
1993October 31March 71 hour, ACST to ACDT
1994October 30March 201 hour, ACST to ACDT
1995–2005last Sunday in October, 02:00last Sunday in March, 03:001 hour, ACST to ACDT
2006October 29April 21 hour, ACST to ACDT
2007October 28March 251 hour, ACST to ACDT
2008–2037first Sunday in October, 02:00first Sunday in April, 03:001 hour, ACST to ACDT

Clock changes in 2026, 2027 and 2028

The clocks go forward 1 hour (ACST to ACDT) on October 4, 2026, October 3, 2027 and October 1, 2028 at 02:00 and back 1 hour (ACDT to ACST) on April 5, 2026, April 4, 2027 and April 2, 2028 at 03:00, local time.

Also on UTC+9:30

Broken Hill (Australia) and Darwin (Australia).

Clocks next door since 1970

  • Broken Hill (424 km): same time except 98 days in 1982, 1990, 1992, 1994 and 1995.
  • Melbourne (656 km): usually 30 minutes ahead; different on 107 days in 1971–2026.
  • Eucla (970 km): usually 45 minutes behind; different on 7,754 days in 1971–2026.
  • Hobart (1,163 km): usually 30 minutes ahead; different on 775 days in 1970–2026.
  • Sydney (1,164 km): usually 30 minutes ahead; different on 163 days in 1971–2026.

How it compares

Standard time has stayed at UTC+9:30 since 1899.